Outdoor equipment, such as a sleeping bag or a jacket, is traditionally manufactured with a specific amount of insulation depending on the intended outdoor use. For example, a sleeping bag with a 20° F. temperature rating means that the sleeping bag is intended to be used in situations where the outdoor temperature is no less than 20° F. The amount, type, and configuration of insulation within the sleeping bag dictate the temperature rating of the sleeping bag, the lowest outdoor temperature at which the sleeping bag should keep an average sleeper warm and prevent the risk of hypothermia. This same concept applies to other types of outdoor equipment, such as jackets, pants, gloves, etc. Traditional insulation materials include down and synthetic batting. The loft or thickness of the insulation material creates pockets of dead air space that hinder the transfer of heat from the user's body thereby keeping the user warm.
Since insulation is traditionally sewn into an article of outdoor equipment, the insulating properties are fixed. This can create uncomfortable and undesirable situations for a user. If the user's needs differ from what is offered by the equipment the user has on hand, the user must suffer the existing level of insulation, or add or remove redundant pieces of equipment in order to attain the required level of insulation. For example, in cold weather situations, a camper may be forced to layer various articles of equipment to achieve increased warmth. This increases the number and weight of articles that must be carried by the camper during his or her trip. In contrast, in warm weather situations, a camper's equipment may be uncomfortably warm.
As such, consumers generally have to buy various articles of outdoor equipment for different situations. For example, a camper must buy different types of sleeping bags for different times of the year. A sleeping bag with a very low temperature rating is needed for camping during the winter, but would be uncomfortably warm in the summer. Similarly, consumers generally have to buy coats or jackets with different amounts of insulation for different seasons and/or situations. For example, a highly insulated coat is desired for extremely cold winter months, whereas a jacket with less insulation is desired for fall and spring months.
Accordingly, there is a need for outdoor equipment that allows a user to adjust the amount of insulation depending on the conditions when used.